The present invention relates generally to navigation systems and more particularly to a navigation system having a base station permanently mounted in the car and a handheld device which is portable relative to the base station and provides a subset of functionality apart from the base station.
Vehicle navigation systems with full functionality, including a full road database and turn-by-turn instructions, etc., are typically installed in a vehicle. Another known navigation system, developed by the assignee of the present invention, is “portable” in that it can be transferred from vehicle to vehicle, but are not really practical to be carried by a user. The known in-vehicle navigation systems are not sufficiently portable to be carried by a hiker. The known navigation systems include user input and output devices for communicating with the user, navigation sensors, such as a GPS receiver, accelerometer, gyros, vehicle speed sensor and other sensors. The navigation system further includes a database of roads and destinations and software for calculating routes from the present position of the vehicle to selected destinations in the database.
Handheld GPS receivers comprising a display, input buttons and GPS receiver are also known. These handheld devices are often used for hiking, boating or similar activities, but are insufficient for performing turn-by-turn instructions in a vehicle.